you dont have to upload to imageshack (I use imgur) just click on the attachments Choose File button and then open the pic you want to post from whatever folder it’s in.
If it’s a pic in google say just copy the image address type [ img ] paste the address immediately after with no gaps then type [ /img ] at the end with no gaps again
The pic here is using first method (I hope)
There should be no gaps anywhere with the second method i’ve had to put gaps in the brackets otherwise they don’t post